Automatic compression refrigerating apparatus.



G. P. CARROLL.

AUTOMATIC COMPRESSION RBFRGERATING APPARATUS.

APPLICATION FILED APR.12.1907.

3 SHEETSSHBBT 2.

Patented Nov. 24, 1914.

n, QN

G. P. CARROLL.

AUTOMATIC COMPRESSION REPRIGBRATING PPARATUS.

APPLICATION FILED A1 1z.12,190v.y 1 1 1 8,737

, Patented Nov. 24, 1914..

3 SHEETS-SHEET 3.

GEORGE 1?. CARROLL, OF 13R11)(.itEll?ORT, CONNECTICUT.

AUTOMATIC COMPRESSON REFRIGERATING APPARATUS.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed April 12, 1907. SeriaLNo, 367,836.

Ib (IH w71 om it may Conce/n Be it known that nl, Grenen P. (lixrxiorr. a citizen of the United States, 'residing at Bridgeport, in the county ot Fairfield and State of Connecticut, have invented a new and useful Automatic Compression Retrigerating Apparatus, ot' which the following; is a specification.

M v invention relates to improveaicnn3 in compression retrifgferatiner apparatus. cepe- Ciallv those of small capacities where the at tendance of an'engii'icer would he unpraeti Cable. ASuch planty range. in their rapaci ties, from plants adapted for domestic purposes. up tu plants having; a retrie'erating; capacity of 2O tons per il hours.

The means employed consist ot automatic meansl wherebv the quantit;Y ot retrigeratingr Huid passing through the expansion valve and the. quantity oi' cooling tluid ing` into the condenser and water jacket are made to Correspond with the requiremonta` of the system while the Comin-essor is run-- ning, so as to make possible the maintenance of a predetermined temperature around the expansion coils', wherebv the startiru;Y and stoppingr of the Compressor is made to depend on the rise and `tall of temperatiue, Within predetermined limits, Vin the refrigerator inelosing the expansion eo' and whereby the power driving the compresmr is shut ott it an abnormal amount ot' poner. indicating a dangerous condition, is required to drive the compressor.

vhile other refrigferatingy fluids, inav be used, it is to be understood in the followingl description that anhydrous ammonia the fluid preferred, as on the whole it produces the most saiistaetorv results.

in the drawings, 'Figure l is a diagrammatic representation ot' rnv invention showing the partsin detail and their connections. Fie'. Q is a front elevation of an electrie eX- pansion valve and a vertical section of a pressure regulating valve with their conne@ tions. Fig. 3 is a side elevation ot a switch shown in the preceding iigure. Fig. i ia a vertical Section of said expansion valve. Fig. is a vertical cross-section ol an electrie water valve with its couneetiona. Fig, (i is a front elevation ot' said water valve. And Fig. 7 is a vertical crosssection of a moditied torni of the valve shown in Fig. 5.

An expansion coil C is convoluted in a suitable compartment l of a refrigerator li. The coil may be used to refrigerate the air in the, compartment so that the air will eireutate tln-ough the refrigerator after being directly chilled by the coil. Or a suitable brine may be placed in the compartment so that the coil will refrigerate the brine and the air will circulate through the refrigeru ator after being;r chilled by the brine. In the latter case the brine can be carried below the freezing point so as to freeze potable water in an ice can 2, placed so as to be sur rounded bv the brine.

The outlet end of the expansion coil C europeesr from the refrigerator and leads into the inlet side oi' a eompressor K, being intermediatelv provided with a back or low pressure gale li. The Compressor is driven by a suitable motor, preim-abitT au eleetri-f: motor M, ,u'eferablv through a belt 3. neu the compressor 1s in operation it draws spent gas from the expansion eoil, eon'lpresses it in the manner Common to such machines, and forces the compressed gas thi-ouah a high pressure pipe 4, intermediatelv provided with a head or high pressure gage ll. through an oil Separator' O, and into a condenser l).

pipe leada from a source of water suppl'v. is internnaiiately provided with an ele( trie water xalve Vv', and leads into the con denser ll. The cooling water, by its con tact with the walls of the passages containiner the hot. compressed gas from the compressor, removes the heat of compression and eondenses and liqueiies the ref rigerating tluid. From the condenser the pipe 5 leads to a water .iaeltet 6 surrounding the compressor cylinders of the compressor K, where it ren'ioves a part of the heat of compression betere passing off into the waste. l'n some. constructions the cooling water is led first to the compressor water jacket and thence to the condenser; but the better practice is to reverse the order so that the coldest water ma)v cool the coldest gas, thereby reducing;- the tinal pressure of the gas and making the head pressure less and the power required to operate the compressor correspomlinglv less. The condenser D and water jacket Ggwith their connections, constitute fluid cooled 1n ians for condensing the coinpresscd gras. although the water jacket may be omitted it desired.

From the condenser the pipe 4 transmits the hunched fiuid to a container F, and thence to an electric expanslon valve l". From the valve E the inlet end of the expension coil C leads through a. pressure regulating valve l`F4 into the refrigerator B. In actnai practice it is advisable to have the inlet side of the compressor l( and the valve ll as near as practicable to the place to be ref erelid so as to jjnevcnt a useless refrigeration of the outside atmosphere. And the valve l. ii' made accessible for convenient adjusting. nxay be placed within the space to be refrigerated; or, if a brine tank is used. as near to it as practicable. A stop valve 7 may be placed in the water supply pipe 5 ahead of the valve W and :stop valves S, 9, 10, 11, 12 and 13 may be placed at convenient points in the ammonia circuit to disconnect parts of the system when desired. All these valves are to be open when the plant is to be operated for circulating the ammonia. ll'hen, however. a vacuum Vis to be pumped in the s vstem preliminary to chargingr` the valve 9 is closed.` the val ves T, 8, 10. 1,1, 12 and 13 are opened, and an air valve 9a, between the valve 9 and the delivery side of the compressor 1. is opened. After a vacuum has been pumped.v the valve -Sla is closed. the compressor is stopped and the valve 9 is opened. An ammonia charging valve 1-1 is placed in the pipe l beyond the container F and the valve 12. A drain valve 15 is placed at the lowest part of the pipe 5 to drain the water jacket and condenser when the plant is to be shut down for the season. Front the bottom of the oil separator O a pipe 1o provided with a st'op valve leads into the crank chamber of the compressor K; this valve is to be kept closed except on the infrequent occasions when it is desired to drain the oil separator 'of accumulated oil.

From a generator G, located. as at a central power station, mains 1T lead through a hand switch S to and back again from thtl motor lll. Between the switch and the motor anautomatic circuit breaker ot' any approved type. is placed to automatically shut down the motor in case extremely abnormal conditions develop in the plant as manifested by the requirement ot' a very high current to operate the motor. rBetween the circuit breaker and the motor is placed a starting rheostat R. having a solenoid The casing of the valve l has intermediate between its inlet and outlet parte. a horizontal valve seat 1f). A needle valve 2G is adapted to occupy and cl 'lv from above and when ne? '1 is pressed down` upon iis spring 2t. abultnif." a, inside of the top cap using ano at its other end against the top of the needle valve. The upper part of the valve is provided with a projecting' pin 23, adapted for engagement with the slotted end of an inner lever 2&1-, extending in a horizontal direction. The other end of this lever is secured to or made of one journaled at one end in the back wall of the casing and passing out through the front of the casing where it is provided with 'i suitable stuffing box. An outer lever 2G 1s secured to the outer end of the lever shaft and extends in a horizontal direction oppo` site to that of the inner lever.

Pivoted at 27 on the extended outside part of the casing of the valve E is a three-.part lever 28 having its main arm 29 extending horizontally towardy and terminating in a position just above the outer end of the outer ylever 26. The cxtreme end of the mainarmw29 is provided with an adjusting screw 30 so that the contact of the main arm 29 and the outer end of the outer lever26 may be suitably regulated. The length with which the screw projects below the main arm determines the depression of the outer lev r 2G and the consequent elevation of -the -inner lever 24, theipin 23, and the needle valve 2O from olf its seat.

31 extends upwardl and a lower arm 32 extends dewnward from the pivot 27. y

An electro-magnet 33 is placed immediatcljvY under the main arm 29 and when energized by the' passage of 'a current depresscs the main arm downward so as to be incontact through the adjusting screw 30 with the outer end of the outer lever 26. The depres` sion ol the main arm 2S) overcomes a spring 34 ywhich keeps the main arm elevated when the magnet is not energized or when the main arin is not locked in a depressed posi-v tion. The depression of the main arm 29 throws the upper arm 31 to the left and the lower arm S2 to the right.

A dog pivoted at 36 on the extended outside part of the casing of the valve E, has a, tooth 37, which rests upon the inclined outside of the extreme top of the upper arm 31 while the main arm 29 is elevated'. But with the depression of the main arm by the energizing otl the electro-magnet the upper arm 31 slips inside of the tooth B7 and there continues in a locked position after 'the electro-magnet 33' is no longer energized. A switch 38 is pivoted at 39 on the extended outside part of the casing of the Valve Eand connects the electro-magnet 33 as hereinafter stated. This switch has two limit l0 and 41 and also a Weight arm inter` im hate between them and ending in a small l.dobnlar weight 42. Both these limit arms are adapted in turn to be engaged by the lower end of the lower arm 32 as it is moved to the right by the depression of the main arm 29 and back again by its elevation.-

VVhen the electro-magnet 33 is energized, the tii'st effect of depressing the main arm 29 is to lock the upper yarm 31 into engagement with the tooth 37; also the lower arm 32 is piece with a lever shaft 25,

Substantially at` right angles to the main arm an upper arm` thrown` against the limit arm so as to,

thrust it to the right and to throw the center of gravity of the weight 42 to theright of the center of the pivot 39. This shifting of the weight 42 ther; opens the switch and breaks the flowv of current through the electro-magnet. The time required for this last above the dog 35. lVhen the electro-mag-- net 43 is energized it lifts the dog and thereby releases the upper arm 31. This action permits the spring 34 to raise the main arm 29, the electro-magnet 33 being, as just seen,

in a condition of non-energization, The

lifting of the main arm 29 throws the lower arm 32 against the limit arm 41 so as to thrust it to the left and to throw the center ofgravity of the weight 42 to the leftof the center of the pivot 39. This shifting of the weight then closes the switch 38 and makes possible a iow of current to again energize the electro-magnet 33.

The pressure reducing valve P, interposed in the expansion coil C, preferably consists of a lower casing 44 having a perforated lateral'mtrance boss 45 and an outlet 46. To the top of the lower casing is bolted an upper casing 47 so as to secure between`the .fianges of the casings a diaphragm 48. A

coiled-spring 49 tends to force thev diaphragm downward. An adjusting screw 50,

extending through the top of the upper casing, is used to adjust the pressure of the spring. Secured to the under side of the diaphragm is a depending slotted bar 51.

the bar is a conical valve plug Threaded into 52 extending up into its slot. An entrance piecev 53 rests in the boss 45, having a central passage from its outer end terminating in 'a .conical valve seat 54 on its under-side adapted for the seating of the valve plug 52 when the diaphragm 48 and the depending slotted bar 5l are forced upward. The entrance piece is kept in its predetermined position preferably by set screws 55 piercing the valve casing.

The casing of the electric water valve W has an oblong port 56 with its longer axis vertical. A gate valve 57 is adapted to partially or wholly open the port according to its position of elevation. .A valve stem 58 is secured at its lower end to the top of the valve and passes up and out through a detachable cap 59-closing the casing and being provided with a suitable stuffing box. A spring 60 coiled about the valve stem and abutting against the inside of the cap and the top of the valve keeps the .valve closedlwhen not opposed by a greater force,y `The valve stem 58, above the @ap 59 is prvdeaewaa say three, collar heads 61, 62 and 63, which should be longitudinally adjustable. In Eig. 5 the stem 58 is shown as threaded and all three collar heads` are correspondingly threaded and are kept in any desired position' by set screws. In the alternative construction shown in Fig. 7 the valve stem consists of a lower valve stem 58,`having a threaded socket 64, and an upper valve stem 58b correspondinglyl threaded at its lower` end for longitudinal adjustment in the socket 64. In this latter construction only the lower collar heads 62a and 638L are threaded and provided with set screws; and the upper valve stem 58" and the collar head 61a receive their proper longitudinal position by a proper adjustment in the socket 64.

A solenoid 65 has a core 66 insulated. at its top and provided with an 'arm 67 projecting at rightangles from the core above the solenoid and below the insulated top. The outer end of the arm 67 has a vertical face. A dog 68, pivoted at 69 on an extension of the lower end of the core 66, has a lower arm ,70 which, when the core 66 is in its lowest spring on its under side at the right ofl the pivot 74, and a coiled spring 76, attached to its upper side at the left of the pivot 74 and tending to keep in an elevated position the left end of the double switch arm., The arm is insulated between the pivot 74 and the spring 76. The right end of the arm beyond the flat spring 75 has a contact surface adapted to close a circuit on contact points 77 and 78, which are insulated from each other.

A double locking arm 79 pivoted at 80 by means of a tooth 81 projecting from the upper member of the locking arm, is adapted to engage the left end of the switch arm 73 from above, so as to'hold the right end of the switch arm elevated away from the contact points 77 and 78. A coiled spring 82, attached to the lower member of the locking arm, tends to pull that member to the left so as to force the upper member and the tooth 81 to the right. Zhen out of engagement the left end of the switch arm 73 rests on the upper face of the tooth 8l. When the tooth 81 is engaged as shown with the left end of the switch arm 73 and also when that end rests ony the upper face of the tooth, the outer face of the lower member of the lockingV arm 79 is in a vertical plane just a trifle to the vleft, of tpe ar1n6.

w yA detent lever 83, piv'oted at 84 and supported by an' extension of the cap 59, is nrm'a'lly kept'in'nearly a vertical position by a coiled yspring tending to pull it to the right. Just above the pivot 84 the detent lever 83 has a detent 86 adapted to engage from beneath and to lock in an elevated position whichever one of the adjacent collar heads it may be under. The extreme top of the detent lever 83 has a pin 87 adapted on occasion to engzge and keep in position a lock extension 88 extending to the left froml the upper member of the double locking arm 79. An electro-magnet-90 is operative when energized to pull the detent lever 83 to the left in opposition to the spring 85. From the mains 17, through a` resistance 91, a branch line 92 leads to the solenoid 65. From the solenoid a line 93 leads to the contact .point 78. Aline 94 leads from the pivot 71 back to the mains 17 on the farther side of the motor M. A liiie 95` leads from the. lin'e 93 to a circuit breaker 96, of the usual kind, and thence through a resistance 97 havingl a core 98 back to the mains 17 also on the farther side of the motor M. The resistance 97 operates on the core 98 so as, by opening the circuit breaker', to break the circuit when the current exceeds a predetermined limit.' The-circuit breaker 90 is providedwith a suitable arm 99, which serves the double purpose of being a hand lever yfor closing when'lifted the circuit and also is adapted to be lifted with like effect by the elevation of a core 100 having a pin 101 for engaging th'e arm 99 when a solenoid y102 containing the core 100 is energized.I A line 103 leads from the line 93 through a resistance 1011 back to the mains 17 also on the farther side of the motor M. A branch line 105 leads to and through the solenoid 102 from the' branch line 92 to the Contact point 77. From the. mains 17 between the automatic circuit breaker A and the contacts of the rhcostat l through a resistance 10Gv a branch line 107 leads to and through the solenoid 18 to a contact point 108 where com tact can be made through a hantl switch `10,9 back to the generator G. Such a contact' energizes the solenoid 18ct thye rheostat Il to turn on the full current for starting the motor M. The hand yswitch is also adapted to make contacts at 110 and 111 respectively. Through a resistance 112 a branch line 118 leads from the branch line 107 to the right et the resistance 1013 to and through the electroanagnet 90 to the contact point 110. From the mains 17 bet\\'een the rheostat ll and the motor El aigsaneh 'line 11i-leads` to and through the. tav-:itch and the electroniagnet 3S back to the mains on the farther side et the motor. From the branch line 118 between the resistance 112 and the electro-magnet 90 a branch line 115 leads to and through the electro-magnet 43 back to the branch line 113 onvthe farther side of the electro-magnet 9 Within the refrigerator B is mounted a thermostat T of any approved type.l In the form shown it consists of a rod 116, subject to expansion and contraction -With increases or decreases of temperature, attached to a lever v117 adapted to make electrical contact either at 118 or 119. A,solenoid 120 contains a c'e 121 toothed at its top and having a switch 122 attached to its lower extremity. ,When the core is lifted b v the temporary energization of the solenoid its tooth is normally engaged by a detent 123, whichv may, however` be drawn out of engagementl With the tooth by the energization of an electro-magnet 124. From the branch line 107 betjveen the solenoid 18 and Ithe contact point 108 a branch line 125 leads to the mains 17 between the switch 109 and the generator, which branch line is closed when the switch 122 is elevated. From the branch line 113 between the resistance 112 and the electro-magnet 90 a branchline 126 leads to and through the solenoid 120 to the contact point 118. The lever 117 being conductive from its extremity to its pivot 127, a branch line 127a leads from the pivot to the contact point 111. From the branch line 126 between the resistance 112 and the solenoid 120 a branch line 128 leads to and through the electro-magnet 121 to connect at 129 with the branch line 113 between thev electro-magnet 90 and the contact point 110 'and thence the branch line 128 leads to the contactpoint 119.

The parts are so constructed in relation to cach other that a greater current is required to .pass through the resistance 104- than through 'the resistance 97 and the automatic circuit breaker A does not become operative until after the passage. of a current through the. resistance 104 has failed of its intended purpose as hereinafter explained. There are therefore three means as shown for turning on and increasing the supply of condenser water: (1) by a Icurrent through the contact 78 and the line 94; (2) by a greater current through the resistance 97; and (3) by a .still greater current through the resistance 104. lf this last fails to supply a sufficiency of cooling water, as by the total failure of water supply, causing an excessive power to operate the machine; then the circuit breaker A becomes operative to shut off the current and to stop the machine.

The method of operation is as follows: Before; starting the compressor` for the stason. the valve 7 is opened and, until thc condeuter D and the water jacket G are filled, the valve stem 58 is held b v hand in an elevated position. yThe coiled spring 21 is now (as a second condition) holding depressed the needle valve 20 and the coiled spring 60 is also holding depressed the gateyalve 57,

` by any accident vand the left end of being below the detent v86 nthe double. switch arm 73 resting on top of the tooth 81. It is first assumedthat the plant is operated without the use of a thermostat.l In that case the hand switch S is closed and the hand switch 109 is brought to contact at 108. This acthe collar head 61 tion permits a slight current to flow through the automatic cut ofll A, the resistance 106, the branch line 107, the solenoid 18, the contact point 108, and the hand switch 109 back to the generator G. The energization of the solenoid 18 actuates-the rheostat R and closes the circuit to the motor M and thus starts the compressor K. Simultaneously through the branch line 114, the switch 38 and the electro-magnet 33 back to the mains 17'7 a slight current energizes the electro-magnet 33 and thus, through theconnections to the needley valve 20, opens the valve E; and at the same time through the resistance 91, the branch line 92, the solenoid 65, the line 93, the contact point 78, the double switch arm 73 (being then in contact with the contact points 77 and 78) and the line 94 back -to the mains 17, a slight current energizes the solenoid 65 and thus acts upon the core 66" and the dog 68, which is pressed against the valve stem 58 by the spring 72 as soon as the pin 71, to act upon the collar head 61 and by lifting the valve stem 58 to open the valve YV. The plant is thus in operation either for pumping a vacuum, as will be 1ndicated by both gages L and H, preliminary to charging with ammonia; or, 1f that has already been done, for doing the Work .of refrigeration, the liquid ammonia vaporlzing as it passes through the valve E and condensing water being supplied through the valve W. The charging of the system, after a vacuum has been pumped and the air valve 9a has been closed and the valve 9 has been opened, is accomplished, the compressor running slowly on part current, by connecting a drum of anhydrous "ammonia to the pipe having the valve 14, by closing the valve 12, by opening the valve 14, and by slightly opening the outlet valve on the drum. During this process the valve 14 is manipulated as a hand expansion valve so as to gradually charge the system, the ammonia finally becomingr liquefied in lthe container F. The valve lE does not interfere With this process as it remains constantly open while the compressor is running. Nor does the valve P `interfere because the process of chargingis carried on with a low back pressure; and 1f, the back pressure should be excessive,.the valve P would operate as a safety device to prevent liquid ammonia passing intothe compressor.

The employment of current 1n opening the valves E and W is only instantaneous.` For the depressingA of thev main arm 29, when the electro-magnet arm 32 is rotated to th'e right.

lifted from Y collar head 61 33 is energized, ro-l tates the upper arm 31 to the left on the pivot 27 until the three-arm lever 28 is locked in positionby the dog 35 through its tooth 37; and at'the Same time the lower` The consequent engagement of the lower 'arm with the limit arm 40 and the thrusting of the weight 42 to the rightof the center of the pivot 39 opens the switch IIgll'and shuts off the flow of current through the branch line 114. And the lifting of the core 66 lifts the collar head 61 and through it forces the detent 86 and the detent lever 83 to t-he left, overcoming the coiled spring 85 in so doing. Just as soon as the collar head 61 passes the detent 86, the coiled spring 85 forces the detent 86 against the stem 58 under the collar head 61, thus locking the valve stem andthe valve in a partially open position as shown. As the core 66 is being elevated and before the detent lever -is forced to the left-f, the insulated top of the core strikes the insulated flat spring 75 and thereby `tends to break the cont-act of the double switch arm 73 with the contact .points 77 and 78. But at the instant of striking, the face of the arm 67 is just opposite the face of the lower member of the double locking arm 79 and thereby holds the t th 81 so thatthe left end of the double s itch arm cannot drop below the tooth. An inst-ant later, however, the arm 67 has passed above the lower member of the double locking arm 79 and the core 66 has fully compressed the fiat spring 75 so that the current through the contact points 77 and 78 will be completely broken as soon as the tooth 81 can be forced to the leity The tooth is so forced tothe left an instant later by the down pressure upon it of the left end of the double switch arm T3 and especially by the movement to the left of the pin 87 along the lock extension so as to depress the lockextension 88 as the detent lever 83 rotates to the left on its pivot 84. This rotation takes place, as just stated, while the collar .head 61,is passing the detent 86. The breaking` f the current under normal conditions denergizes the solenoid 65 so that the core 66 and its dog 68 resume their original position. All the parts are now in the position shown in Fig. 5. The effect of this entire operation is to leave the locked by the detent-86, lthe valve W open to a normal degree and the current through the branch line 92 broken.

It is apparentthat b pro erly adjusting the screw 30 the valve i can e opened sufficiently to permit of maximum quantity of ammonia required by the system. And asimilar adjustment of the collar head 61, or, if thestructure shown in Fig. 7 is used, of the upper valve stem 58 in the socket 64, will provide for a normal suiiciency of condensing water. The bottom collar head 63 or 63a is adjusted low the transmission of the enough on the valve stem so that, when it is lifted by the dog 68, it will lift the gate valve 57 to tliepoint permitting of the maximum iow of water needed for the condenser D and the water jacket 6 even under unusual conditions. The one or more intermediate collar heads 62 or 62a may then be adjusted sothat all the collars will be equidistant on the stem. `For every temperature t0 be maintained in the expansion coil C (which will be about l0", more or less, lower than the temperature to be maintained outside'of thecoil in the compartment l) there is, as shown by the ammonia tables, a cor-I responding maximum density and pressure. This maximum decreases with the decrease of the temperature to be maintained. Thus While va gage pressure of about 28 lbs. would make possible a temperature in the coil4 only down to 15o F., a gage pressure of aboutK 6 lbs. would make possible a temperature in the coil as low as 150 F. It is impossible,

however, to permanently adjust such a valvey as E, or any hand operated valve, so as to obviate overfeeding or uiiderfeeding.

In ease of underfeeding, the system does not operate to its full capacity nor at its highest efficiency for the'teniperature to be maintained, In case of overfeeding: l. The expansion coil is likely to frost outside of the refrigerator at the return end, beginning from the valve S and thence oftentimes as far as the compressor itself, at the ex-A pense of the efficiency of the plant. 2. yLiquid ammonia may be thus conveyed into the compressor eylinder,'producing a dangerous situation similar to that where water from the boiler is carried into a steam engine cylinder. 3. As just seen, if the vapor is too dense, it is impossible to produce the desired lowness of temperature in the coil. Therefore the valve E is adjusted to permit of the maximum density and then, to limit the density of the vapor in the greater part of the coil, the pressure regulating valve If is provided. By the opening of the electric expansion valve E, the ammonia is permitted to vaporize and to become as dense as may be in that part of the expansion coil C '.etween the valve E and the valve P. But in all of the expansion coil lying beyond the valve 'P the density of the vapor is autoniatiL cally limited', to any degree of density required, b v properly adjusting the screw 5t). When the vapor becomes sufficiently dense it tends to overcome the force of the coiled 'spring 49, as adjusted by the position of the screw 50, to lift the diaphragm 48 and the bar 51 so as to force the valvev 52 to its seat, and thus to check the flow of ammonia. l3nt as the gas in the expansion coil C is being at the same time drawn off by the compressor K, the tension of .the gas upon the diaphragm tends to diminish so asto permit the coiled spring to force the valve downadjusted so that, when ward. These two opposing tendencies con'- tinue lto regulate the position of the valve so ylong as the valve E is open. In practice the valve P thrugh` its screw is first adjusted to produce the desired temperature in that part of the expansion coil lying beyond it. This is' done by trial, observing the back pressure gage L, and in view of the known relation between pressure and temperature as shown in the tables. The valve E is then open, vapor-ization will occur between itself and the valve P.

The use of the pressure regulating valve l alone as`an expansion valve would not produce certain desirable results obtained with a hand regulated expansion'valve when attended lby an engineer. For when a nonautomatic compressor is to be stopped, the best `practice requires the engineer to shut ofi`v the hand expansion valve and let the conipressor ru'n a few strokes until the back pressure gage indicates a few pounds above vacuum. By thus shutting oif the expansion coils he relieves them from strain. The same result is accomplished with my invention. 'For the turning off of the power, as will be described, permits the valve E tio close at once; but the momentumV of the moving parts causes a few more strokes of the compressor K until the back pressure is carried down to a low point. As the delivery valve leading from thecompressor K to the high Ipressure pipe 4 is, according to the usual practice, a spring check valve, no gas can return; and the expansion coil and the compressor cylinder remain under low pressure so long as the compressor is inactive. T hen when the current is turned on, the valve lil opens immediately and the liquid ammoniay begins to vaporize immediately into the expansion coil Grand the compressor K draws out the spent gas as fast as it passes through the coil. If tlie'pi'essure regulating valve P was used as an eXpansion valve, a relatively high pressure would be maintained. in the low pressure side of the svstem while standing idle. Furthermore, (in starting up, there would be much more spent Yto be drawn from the expansion coil before the working fluid could begin to refrigerate. l

The condensation of a gas such as ammonia depends on two factors; namely, the pressure to which the gas is subjected and the heat of the gas as compressed. If it is driven into a condenser sufliciently supplied with cooling water, it will liquefy at a c omparatively low pressure, say 160 to 1S() lbs. But if the condenser water is insuflicient lin quantity or too warm, liquefaction takes place at a higher pressure. In this'latter condition, the pressure of the gas in the pipe 4 beyond the delivery valve of the compressor K, is very high. Consequently to overcome such excessive pressure so as to iot The greater the quantity of condensing water supplied to a refrigerating system, the

less is the power required to operate the comressor. But in every plant depending for lts power directly or indirectly upon the consumption of fuel, a point is reached wheretlie increased cost of the water supplied, if metered, overbalances the saving in power. The point of maximum economy can be determined by experience, in view of therelative cost of power and water. My lnvention makes it possible to maintain the ascertained economic ratio, varying with diiferent plants according to` the cost of power and water, between the quantity of condensing water and the amount of power required to operate the compressor. This is accomplished for ordinary conditions, as before stated, by regulating the initial lift of the gte valve 57 through the collar head 61 or t e valve stem 58". But sometimes it happens that the current required to drive the .motor M increases beyond what would be suicient to pass through the resistance 91 alone and becomes suliicient to pass through the branch line 92, the solenoid 65, the line 93, the line 95, the circuit breaker 96 and the resistance 97 back to the mains 17. This would occur while the motor M was runningand when the supply of water passing into the condenser D, by reason of becoming heated in its source of supply, had

. become insuflicient to remove enough of the heat of compression for the economical operation of the plant. In other words this would occur when, as indicated by the high pressure gage H, the supply of water was insufficient to keep down the head pressure to the point of economical operation.

The effect of a current passing through the resistance 97 is to again energize the solenoid 65, to lift the core 66. to engage the dog 68 with the collar head 62 so as to lift the stem 58 still higher until the collar head 62 gets above the detent 86 in a locked position. action of the core 66 on the fiat spring 7 5 is to keep the double switch arm 7 3 from oil' the Contact points 77 and 78 until the detent 86 lockrthe Collar head 62 on its under side,

when the tooth'l again becomes operative to lock the double switch arm. As the gate valve 57 is lifted 'up to a positlon corresponding to that of the collar head 62 over the detent 86, the supply of water to the condenser isy correspondingly increased. The normal elect of such an increased supply of condensing water is to decrease the power required to operate the motor Consequently,.avhen `this point 1s reached, the culv'lent no longerypasses through the resistance 97 and the valve remains locked in its and is held by it At this time the only' secondary position, and without the expenditure of ower, until the current is shut o from e motor` and the valve is closed in the manner'hereinafter explained. Butshould it happen, from the continued heating of the water in its source of supply or from any other reason, that this increased supply of water isinsuiiicient to reduce the power operating the motor and the power continues to increase, the current passing through the resistance 97 will soon lift .the core 98 so as to act on the circuit breaker 96 and thereby break the current ilowing through the resistance. By' this action the arm 99 drops on the 'oint 101. Under these circumstances, also, t e `valve remains locked in its secondary lifted position, and without the expenditure of power, until the current is shut olf fromthe motor and the valve is closed. In other words this further opening of the valve either brings the power back to normal and so prevents .powr from being used to hold open the valve; or, if the power is not brought back to normal, the power is automatically shut off from the solenoid 65 so as no longer to be employed in holding the valve open. y

Should the power required to operate the motor continue to increase beyond the pointsuicient to open the circuit breaker 96, a branch current will eventually pass through the branch line 92, the solenoid 65, the line 03, the line 103 and the resistance 104 back to the mains 17. The energization of the solenoid 65 again lifts the core 66 and in consequence the do-g 68 engages the collar head 63 and lifts the stem 58 to its hl hest elevation until the collar head 63 gets a ove the detent 86 and is held by it ina locked position. Here again the only efect of the core 66 on the Hat spring 75 is to keep the double switch arm 73 from ol the contact points 77 and 78 until the tooth 81 again interlocks with it. It will be observed that, under these circumstances, while some current continues to pass 104, no current is employed in holding the valve lifted to its through the resistance highest position. And l1f operate the water, the currentwill cease to flow through the resistance 104. If on the other hand, the current through the resistance should continue to increase, such a fact is proof that the difficulty does not lie with any ordinary insufficiency of water supply; but that something more serious is responsible. y

The automatic circuit breaker A is so constructed and adjusted` that the current from the generator G passes freely through the mains 17 until from some cause a normal current becomes insufficient to operate the motor M. It is `to be understood, in this connection, that a current which megelyreg iso f sults in actuating the valve W, by passing malIlS.'

through the resistance 104, so as to permit of'a maximum quantity of water flowing through the condenser and water jacket, is simply normal. When, however, the current has exceeded the limit where the maximum quantity of condensing Ewater might remedy the diiliculty, a dangerous condition is reached such ythat the compressor should be stopped until the cause of the difficulty can be ascertained and the trouble be remedied. Such an excess of current may indicate one orl more of several conditions: 1. Breakage or disarrangement of parts in the motor itself. 2. Breakage or disarrangement of parts in the compressor. The most common accident of this nature is where the delivery valve of a compressor cylinder breaks and one of the pieces lodges against the cylinder head in the path of the advancing piston. 3. Abnormally high head pressure necessitating an excessive current for the operation of the motor. This may arise from the shutting oil' of the water supply in the water 4. The passage of liquid ammonia into the compressor cylinder. This might happen if the valve E or the valve P should be improperly adjusted or should get out of order so that more liquid should pass into the expansion coil than could be vapori'zed.

In any of these cases the automatic circuit breaker acts in the usual way to cut ofi' all current from the' system. A

When it is desired to stop the compressor, the switch 109 for an instant is moved to make contact at 110 and then is moved where it will make none of the contacts shown; The breaking of the contact at 108 stops the flow of current through the resistance 106, the branch line 107 and the solenoid 18. The denergization of the solenoid breaks the main current through the rheostat R and thus stops, the motor M. The instantaneous contact at 110 sends a current throu h the resistance 112, the branch line 113, t e electro-magnet 90 and the contact point 110 back to the mains 17. The consequent energization of this electro-magnet draws the detent lever 83 to the left and thus disengages whichever one of the adjacent collar heads is being held by the detent 86.

This disengagement permits the coiled I spring to depress the gate valve 57 and to close the valve W, thus shutting ofil the supply of water at the same time that the power is turned off from the motor and compressor. Simultaneously with the release of any collar head, the rotation of the detent lever 83, through its pin 87 acting on the lock extension 88, moves the tooth 81 to the left. The double switch arm 73 is then acted upon by the coiled spring 76 so that it again makes contact with the contact pomts 7 7 and 78; but as the rheostat is now open no current passes to the'motor M. When sub- 63, the line 103,

sequently the current is urned on to the motor, at the same time, as beforelexplained, that the solenoidg65 is rst energized by a current passing through the contact point 78, a-current also passes through the line 105, the solenoid 102, and the contact point 77 to the doubleswitch arm 73, there uniting with the current passing through the contact point 78. This energization of the solenoid 102 lifts the core 100 and the pin 101 and thereby lifts the main arm 99 so that the circuit breaker 96 is kagain put in operative position. The contact at 110 also sends a current through the branch line 115 to4 and through the electro-magnet 43 back to the branch line 114. The consequent energization of the electro-magnet 43 elevates the dog 35 and thus releases the upper arm 31 -so that the coiled spring 34 elevates the maln arm29 and thus permits the coiled spring 21 to act on the needle valve 20 so as to close the valve E, also at the same time that the power is turned off from the motor and compressor. The elevation of'the main arm 29 moves the lower arm 32 to the left and thus throws the limit arm 41 and the weight 42 to the left so as again to close the switch 38. It is apparent that when the plant is thus operated by the hand switch The parts shown and described of the.

valve W constitute a three stage valve. It is obvious that, ifdesired', the collar head the resistance 104, the line 105, the solenoid 102, the core 100, the pin 101 and the contact point 77 may be dispeused with. When anexcess current passing throu h the resistance 97 opens the circuit brearer 96, the arm 99 will then be useful to lsubsequently close the circuit ,breaker by hand. Under these circumstances the valve has two stages and only two collar heads are necessary. It is also obvious that bythe insertion of more collar heads, intermediate resistances, circuit breakers, solenoids and 'their connections, the number of stages of the valve may be increased above three. On the other hand, by the omission ofthe collar head 63, the line 95, the circuit breaker 9,6, the arm 99, the resistance 97,

the line 1'05, the solenoid 102, the core 100, 4

the pin 101 and the contact point 77, the valve is Qi a very simple two stage type.

ln connection with the automatic circuit breaker A, an automatic form of automatic signaling device may be used to call Iattention to the breaking of the circuit wherl such a condition occurs. This Gong or some other circuit breaker ,as shown is constructed and operated essentially as is the circuit breaker y 96 when operated by hand through the the expansion of arm 99. y

When the system is thermostatically operated all of the above modifications. are possible except that the automatic rheostat R with its solenoid 18, or the equivalent thereof, must be employed. When the thermostat is used the only function A,of the hand switch 109 is lto make continuous contact at 111. The contact points 118 and 119 are adjustable so that, if for instance, the temperature in the refrigerator B rises to 390, the rod 116 will rotate the lever 117 on its pivot 127 so as to make contact at 118; and "a `fall of temperature to 36 willro ate the lever to make contact-at 119. By closing the hand switch S, when .the plant is to be operated, a current passes through the mains 17, the automatic circuit 'breaker A, the-resistance 112, the branch line 1,26, the solenoid 120, the contact point 118, the lever 117, the pivot 127, the line 127,y the contact 111, and the switch 109 ,back to the generator G. The consequent ergization ofthe 1 into .holding engagement with the detent 123 and also closes the switch122. The closing of the switch' Vcauses a current to pass through the resistance 106, the branch line 107, thesolenoid 18, the switch 122 and the line 125 back to the generator. The conselquent energization of the solenoid 18 starts the valves E and W the motor M and opens before. As the temin the 'samemanner as perature falls in 116 contracts until thel contact between the lever 117 and the contact point 118 is broken. Thereupon current no longer passes through the solenoid 120; but the core 121 continues to be held in its lifted position by the detent 123, so that zcurrent throughthe switch 122 still continues to energize n andconsequently the 'plant continues in operation. IWhen, however, a further contraction ofthe rod 116, say after an hours run or less, results in a contact of the lever 117 with the contact point 119, a current then passes through the resistance 112, the electro-magnet 124, the line 128, the connecting oint 129, the contact point 119, the lever 17, the pivot 127the line 127 a, the contact 111, and the switch '109 back to the generator. The consequent energization of the electro-magnet 124 withdraws the detent123 'from engagement with the tooth of the core 121, allowing the switch 122 to drop and thus to break the current through the line of current denergizes the solenoid 18 so that the rheostat R no'w shuts of the current from the motor M and stops the compressor K. Simultaneously a currenty passes through the resistance 112, the branch line 113, the electro-magnet 90,

solenoid 120 liftsthe core the refrigerator the rod4 the solenoid 18 and also throughthe branch line y115 and the electro-magnet 43,y to the connecting point 129, current back to the generator. The consequent energization of the electro-ma ets 43 and closes the valves Eand in the same-manner as before. When the temperature `has risen suiliciently, contact at. 119 1s broken and as it continues to rise #the lever 117 moves over toward the contact point 118 to repeat the cycle of operations.

While inV the drawings only one refrigerating chamber is shown, yet bers may have their separate eX ansion coils branching from the main coil at it leaves the valve P. Hand valves may i each branch coil near the point of branching so that, byfpartiall'yl closing each valve sulclently, the proper vpro vortion of ammonia may pass int'o each -co partment coil.. 'In such an arrangement the thermostat T would be placed in the compartmentI where an enact conformity to a predetermined temperature was most important. If necessary, to prevent the gas being drawn out too rapidly by the compressor 4from any one or more of the branch coils, a similar valve can be placed in each such coil near its return to the compressor..

The valve E is made the subject of claims in my application Ser. No.- 360,055, filed March 1, 1907, entitled Electric expansion valve. A valve similar yin some details t0 the valve P is shown'in my application Ser. No. 351,068, entitled Automatic ex ansipn valve. 'I'fhe valve W is made the sugject'lof claims in my application Ser. No. 364,418, lfiled March 25, 1907 entitled Electric water valve.

I claim: 1 y f 1. In combination an apparatus for drawing in gas and compressing the same, a condenser leading from-said apparatus, means for applying power to operate said'apparatus, an expansion valve leading from said condenser, a pipe' for admitting a cooling fluid to said condenser, a condenser valve controlling .said pipe, automatic means for applying power to open said condenser valve and to vary the extent to which it "is opened according to the amount of power applied 'in operating said apparatus, and automatic means for subsequently closing said condenser valve when the operation of said apapplying power to open said condenser valve Several cham.,

be placed in where it unites with the other and to vary the extent to which it is opened according to the amount of power applied in operating said apparatus, and automatic means for subsequently closing' said condenser valve when the operation of said apparatus is terminated.

3. In combination an apparatus for drawing' in gas and compressing the same, ay condenser leading from said apparatus, means for applying power to operate said apparatus, an expansion valve leading from said condenser, a pipe for admitting a cooling iluid to said condenser, a condenser 'valve controlling said pipe, automatic means for applying power to open said condenser Valve and to vary the extent to which it is opened according to the amount of power applied in operating said apparatus, automatic means.

' operated by such power to shut oi the power so applied in relation to said condenser valve, and automatic means for subsequently closing said condenser valve when the operation of said apparatus is terminated.

4.' In combination an expansion coil, an apparatus adapted to draw gas therefrom and to compress the same, a condenser leading from said apparatus, means for applying power to operate said apparatus, an vexpanss'm valve leading from said condenser into' saill coil, a pi e for admitting a cooling fluid to `saidcon enser, a condenser valve vcontrolling said pipe,vautomatic means for applying power to open said condenserl valve and to vary the extentto which it is opened according to the amount of power applied in operating said apparatus, automatic means operated by such power to shut otl'V the power so applied in relation to said condenser valve, and automatic means for subsequently closing said condenser valve when the operation of said apparatus is terminated.

5. In combination an lapparatus for drawing in gas and compressing the same, a condenser leading from said apparatus, means for applying power to operate said apparatus, an expansion valve leading from said condenser, a pipe forl admitting a cooling Huid to said condenser, a. condenser valve controlling said pipe, a thermostat operative at a high temperature limit to apply power to open said condenser valve and at a lowv temperature limit to apply powerto close said condenser Valve, and automatic means operated by the power applied to open said,

condenser Valve to vary the extent to which it is opened according to the amount of power applied in operating said apparatus.

6. In combination an expansion coil, an apparatus adapted to draw gas therefrom and to compress the same, a condenser 'leading from said apparatus, means for applying power to operate said apparatus, an expansion valve leading from said condenser into said coil, a pipe for admitting a cooling fluid to said condenser, a condenser valve controlling said pipe, a thermostat operative at a'high temperature ,limit to apply power to open said condenser valve and at a low temperature limit to apply .power to cl'ose said condenser valve, and automatic means operated by the power applied to open said condenser valve to vary the extent to which it is opened according to the' amount of power applied in operating said apparatus. Y 7 In combination an apparatus for drawing in gas and compressing the same, a condenser leading from said apparatus, means for applying power to operate said apparatus, an expansion .valve leadingfrom said condenser, a pipe for admitting a cooling fluid to said condenser, a condenser valve controlling said pipe, automatic means Jfor applying power to open said condenser valve and to vary the extent to which it is opened according to the amount of power applied in operating said apparatus, automatic means operatedby the power applied to open said condenser valve-to shut off the power applied in relation to said valve, and automatic means for subsequently closing said condenser valve when the 'operation ofsaid apparatus is terminated. i

8. In combination-an expansion' coil, an. apparatus adapted to draw gas therefrom and to compress the saine, a condenser leading from said apparatus, means for applying power to operate said apparatus, an expansi'on valve leading from said-condenser into said coil, a pipe for admitting a cooling Huid to said condenser, a condenser valve controlling said pipe, automatic means for applying power to Open' said condenser valve and to vary the extent to which it is opened accordingv to the amount of epower applied in operating saidapparatus, automatic means operated by the power` applied to open Said condenser valve to shut oil' the power applied in relation to said valve, and .automatic means for subsequently closing said condenser valve when the operation of said apparatus is terminated.

9. Incombination an apparatus for drawing in gas and compressing the same, a con` denser leading from said apparatus, an expansion Valve leading from said condenser, a pipe for admitting a cooling fluid tosaid condenser, a condenser valve controlling said pipe, automatic means for applying power to open said condenser valve, to start the operation of said apparatus and to vary the extent to which thecondenser valve is opened according to the' amount of power applied in operating said apparatus, and automatic means for subsequently closing said condenser valve and terminating the operation of said apparatus. v

10. In combination an expansion coil, an apparatus adapted to draw gas therefrom and to compress t e same, a condenser leadamava? ing from said apparatus, an expansion valve leading from said condenser into said coil,

. power to open said condenseizvalve, to start a pipe for admitting a cooling fluid to said Condenser, a condenser valve controlling said v pipe, automatic means for applying power to open said condenser valve, to start the operat1on of said apparatus and to var the extent to which the condenser valve is opened according to the amount of power applied inoperating said apparatus, andl automatic @means for subsequently closing saidA condenser valve and terminating the operation of said apparatus. v j

11. InA combination "an apparatus for drawing in gas and cpm-pressing' the same, a

a pipe forfadmitting a cooling fluid to said condenser, a condenser valve controlling said pipe, automatic means for applying the operation of said apparatus and to vary theextentgto which the condenser `valve is opened according to the amount of power ppliedvvinroperating said apparatus, auto- .matic meanfssoperated 'by the power applied .fte-open saidfcondenser valve to shutoff the PQWer applied in relation tov said valve,

` A and automaticme'ans for subsequentlyfclos-` '30 mglsaid condenser valve and terminating 4fthe-opexfatoii of said apparatus.

Y 212.5 In combination an expansion coil', an*

1 apparatusadapted .to draw gas the' refrf` m v and :to Acompress thesame, a condenser"lead'` ing from said apparatus, an expansl'onivalve leading from said Acondenser into said coil, a pipe for admitting a cooling fiuidftol said .condenser,'a condenser valve controlling said pipe, automatic means for applyingfpower to opensaid condenser valve, tofstart the operation of said apparatus and'tovary the f` extent to' which the condenser valve is opened according to the amount of power applied operating saidk apparatus, automatic :means operated by the power applied to open 'said condenser valve to shut ofi' the power applied in relation to said valve, and automatic means for subsequentlyA closing said condenser valve and terminating the operation of said apparatus.l

13. .In combination an apparatus for drawing in gas and compressing the same, a condenser leading'froln said apparatus, an expansion valve leading from said con denser, a-pipe for admitting a cooling fluid to said condenser, a condenser` valve controlling said pipe, a thermostat. operative at a high temperature limit to apply power to open'said condenser valve and to start the operation of said apparatus and at a low temperature limit to applypower to close said condenser valve and to terminate the operation of'said apparatus, anu automat1c means operated by the power apphed to open said condenser valve to varythe extent to 'ratus.

which it is opened according to of power applied l1n operan-,ngy sain 14, In combination an expansion coil, an'

apparatus adapted to draw gas therefrom condenser, a condenser 4 valve controlling said r pipe, a thermostat operative at a high temperature limit to apply power to open said. condenser valve and tostart the operation of said apparatus and at a low temperature limit to apply power to close said condenser valve and to' terminate the operation of said apparatus, and automatic means operated by the power appiie-d to open said condenser valve to vary the extent to which it is opened according to the. amount of power applied .in operating said apparatus.

l5. In combination an expansion coil, a compressor.- to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an ex-y pansion valve for Vtransmittingthe coin densed fluid intorvsaid coil,a condenser valve controlling Saidpi'pe, automatic means for jripening said condenser. valve andA for lockingzit open and further operative wheinthe j power driving said compressor exceeds a predetermined Ytoi-,further open said condenser valve andhof ubsequen'tly cldse it.

16. In combination-7.a expansion coi-l, a compressor to drawgastherefrom to compress 'the sam,e,4 fluid cooled means for condensing the cmpreedf gas, a pipe for supplying cooling fluid to Saidmeans, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe` automatic means for opening said condenser valve and for lock ing it open and further operative when the power driving said compressor exceeds a predetermined limit to further open said condenser valve, to loclrit open and to subsequently close it.

17, In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, an electric motor for driving said compressor, iuid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means,

an expansion valve for transmit-ting the when the power driving said motor exceeds a predetermined. limit to further open said condenser valve and to subsequently close it.

18. In combination an expansion coil, a compressor .to draw gas therefrom and to compressthe same, an electric motori@ driving said compressor, liuid cooled means for condensing the compressed gas, a pipe fdsupplying cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means .sequentlv7 close it.

19. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, -iuid cooled means for condensing the compressed gas, a pipe for supplying cooling luid to said means, an expansion valve for transmitting the condensed fluid into' said coil, a condenser valve controlling said pipe, automatic means for opening said condenser valve when said compressor is started and for llocking it open and further operative when the povver driving said compressor exceeds a predetermined limit to further open said condenser valve and to subsequently close it.

Q0. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an

expansion valve for transmitting `the con-I densed fluid into said coil, a condenser valve controlling said pipe, automatic means for opening said condenser valve when said compressor is started and for locking it open and further operative when the power driving said compresso1 exceeds a predetermined limit to further open said condenser valve, to lockitopen and to subsequentli7 close it.

Q1. In combination an expansion coil, a

com )ressorto draw gas therefrom and to comiress the same, an electric motor for driving said compressor, fluidcooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe,` automatiomeans for applying electric povvcr to open said con denser valve when said motor is started and for locking it open, iviien the power driving said motor exceeds a predetermined limit for further opening said condenser valve, and for subsequentliy closing it.

'22. In combination an expansion coil, a

. compressor to dravv gas therefrom and to compress the same, an electric motor for driving said compressor, fluid cooled means for condensing the coi'npressed a pipe for supplving cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means for applying electric poiver to ope said condenser valve when said motor is started and for lociing it open, when they power driving said motor exceeds a predetermined limit for further opening said condenser valve and for locking it open, and for subsequently closing it.'

23. In combination an expansion coil', a compressor to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an expansion valve for transmitting the con.- dcnsed fluid into said coil, a condenser valve controlling said pipe, automatic means for opening said condenser valve and for loci;- ing it open and further operative when the power driving said compressor exceeds a predetermined limit to further opensaid condenser valve and to close it When said compressor is stopped.

24. In combination an expansion coil` a compressor to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fiuid to said means, an expansion valve for transmittingr the con densed fluid into said coil, a cmidenscr valve controlling said pipe, automatic means for opening said condenser valve and for locking it open and further operative when the power driving said compressor exceeds -f 'predetermined limit to further open said cr 1ideiiser valve, to lock it open and to close it ivlien said compressor is stopped.

In combination anl expansion coil, a compressor to' draw gas therefrom and to compress the same, an electric motor for driving said compressor, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling uid to said means, an

expansion valve for transmitting the con` densed fluid into said coil, a condenser valve controlling said pipe, automatic means for applying electric power to open said condenser valve and for locking it open, when tbe power driving said motor exceeds a predetermined limit for further opening said condenser valve, and for closing it when said motor is stopped.

' Q6. ln combination an expansion coil, a compressor to draw gas therefrom and t0 compress the same, an electric motorfor driving said compressor, fluid cooled means for condensing the compressed gas, a pipe forsupplyiiig cooling fluid to said means, an

expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means for applying electric power to open` said condenser valve and for locking it open, when the power driving said motor exceeds a predetermined limit for further opening said condenser valve and locking it open, and for closing it when said motor is stopped.

27. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means for opening said condenser valve When said compressor is started and for locking it open and further operative when the power driving said compressor exceeds a predetermined limit to further open said condenser valve and to close it when said compressor is' stopped.

28. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, fluid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means for opening said condenser valve when said compressor is Started and for locking it open and further operative when the power driving said compressor exceeds a predetermined limit to further open said condenser valve, to lock it open and close it when said compressor is stopped.

29. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, an electric motor for driving said compressor, fiuid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means, an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe', automatic means for applying electric power to open said condenser valve when said motor is started and for locking it open, when the power driving said compressor exceeds a predetermined limit for further opening said condenser valve, and for closing it when said motor is stopped.

30. In combination an expansion coil, a compressor to draw gas therefrom and to compress the same, an electric motor for driving said compressor, Huid cooled means for condensing the compressed gas, a pipe for supplying cooling fluid to said means. an expansion valve for transmitting the condensed fluid into said coil, a condenser valve controlling said pipe, automatic means for applying electric power to open said condenser valve when said motor is started and for locking it open, when the power drivingl said motor exceeds a predetermined limit for further opening said condenser valve and locking it open, and for closing it whensaid notor is stopped.

GEORGE P. CARROLL.

Witnesses:

LAURENCE J. GILL, EDWARD F. MEEKER. 

